[Characterisation and measurement of social position in epidemiologic studies]

Evidence of the Relationship between Social Vulnerability and the Spread of COVID-19 in Urban Spaces

Modeling the social-spatial structure of urban spaces can facilitate the development of guidelines aimed at curbing the spread of the COVID-19 pandemic while also acting as an instrument that helps decision-making concerning mitigation policies. The modeling process starts with categorization of urban spaces based on the concept of social vulnerability. A model is created based on this concept and the theory of analysis of social areas. Statistical techniques of factor analysis and geostatistics are applied. This generates a map of social differentiation that, when related to data on the evolution of the contagion, generates a multidimensional model of social vulnerability. The application of this model towards people (social structure) and the environment where they live (spatial structure) is specified. Our model assumes the uniqueness of cities, and it is intended to be a broadly applicable model that can be extrapolated to other urban areas if pertinent revisions are made. Our work demonstrates that aspects of the social and urban structures may be validly used to analyze and explain the spatial spread of COVID-19.

Using ecological socioeconomic position (SEP) measures to deal with sample bias introduced by incomplete individual-level measures: inequalities in breast cancer stage at diagnosis as an example

BACKGROUND

When studying the influence of socioeconomic position (SEP) on health from data where individual-level SEP measures may be missing, ecological measures of SEP may prove helpful. In this paper, we illustrate the best use of ecological-level measures of SEP to deal with incomplete individual level data. To do this we have taken the example of a study examining the relationship between SEP and breast cancer (BC) stage at diagnosis.

METHODS

Using population based-registry data, all women over 18 years newly diagnosed with a primary BC in 2007 were included. We compared the association between advanced stage at diagnosis and individual SEP containing missing data with an ecological level SEP measure without missing data. We used three modelling strategies, 1/ based on patients with complete data for individual-SEP (n = 1218), or 2/ on all patients (n = 1644) using an ecological-level SEP as proxy for individual SEP and 3/ individual-SEP after imputation of missing data using an ecological-level SEP.

RESULTS

The results obtained from these models demonstrate that selection bias was introduced in the sample where only patients with complete individual SEP were included. This bias is redressed by using ecological-level SEP to impute missing data for individual SEP on all patients. Such a strategy helps to avoid an ecological bias due to the use of aggregated data to infer to individual level.

CONCLUSION

When individual data are incomplete, we demonstrate the usefulness of an ecological index to assess and redress potential selection bias by using it to impute missing individual SEP.

Is the socioeconomic status of immigrant mothers in Brussels relevant to predict their risk of adverse pregnancy outcomes?

BACKGROUND

Understanding and tackling perinatal health inequities in industrialized countries requires analysing the socioeconomic determinants of adverse pregnancy outcomes among immigrant populations. Studies show that among certain migrant groups, education is not associated with adverse pregnancy outcomes. We aim to extend this analysis to further dimensions of socioeconomic status (SES) and to other settings. The objective of this study is to identify sociodemographic characteristics associated with adverse pregnancy outcomes, according to the origin of mothers residing in Brussels.

METHODS

We analysed all singleton live births in Brussels between 2005 and 2010 (n = 97,844). The data arise from the linkage between three administrative databases. Four groups of women were included according to their place of birth: Belgium, EU, North Africa, and Sub-Saharan Africa. For each group, logistic regression was carried out to estimate the odds ratios of low birthweight (LBW) and small for gestational age (SGA) according to SES indicators (household income, maternal employment status, maternal education) and single parenthood.

RESULTS

Three key findings emerge from this study: 1) 25% of children were born into a household under the poverty threshold. This proportion was much higher for mothers born outside of the EU. 2) For North African immigrants, SES indicators didn't influence the pregnancy outcomes, whereas their risk of LBW increased with single parenthood. 3) For Sub-Saharan Africans the risk of LBW increased with low household income.

CONCLUSION

In a region where immigrant mothers are at high poverty risk, we observe a classic social gradient in perinatal outcomes only for mothers born in Belgium or the EU. In the other groups, SES influences perinatal outcomes less systematically. To develop interventions to reduce inequities from birth, it's important to identify the determinants of perinatal health among immigrants and to understand the underlying mechanisms in different contexts.

Association between Exposure to Endocrine Disruptors in Drinking Water and Preterm Birth, Taking Neighborhood Deprivation into Account: A Historic Cohort Study

Background: The relationship between preterm birth (PTB) and endocrine disruptor exposure in drinking-water has only occasionally been studied. The objective of this work was to investigate the relation between exposure to atrazine metabolites, or atrazine/nitrate mixtures, in drinking-water during pregnancy and prevalence of PTB neonates, while taking neighborhood deprivation into account. Method: A historic cohort study in Deux-Sèvres, France, between 2005 and 2010 with a multiple imputation model for data of exposure to atrazine metabolites and a logistic regression were carried out. Results: We included 13,654 mother/neonate pairs living in 279 different census districts. The prevalence of PTB was 4%. Average atrazine metabolite concentration was 0.019 ± 0.009 (0.014–0.080) µg/L and 39% of mothers lived in less deprived areas. The individual data were associated with risk of PTB. The risk of PTB when exposed to highest concentration of atrazine metabolite adjusted for confounders, was ORa 1.625 95% CI [0.975; 2.710]. Taking, or not, neighborhood deprivation into account did not change the result. Exposure to atrazine/nitrate mixtures remained non-significant. Conclusions: Even if we took neighborhood deprivation into account, we could not show a significant relationship between exposure to atrazine metabolites, or mixtures, in drinking-water during the second trimester of pregnancy and PTB.

Does area deprivation modify the association between exposure to a nitrate and low-dose atrazine metabolite mixture in drinking water and small for gestational age? A historic cohort study

Birth weight may be influenced by environmental and socio-economic factors that could interact. The main objective of our research was to investigate whether area deprivation may modify the association between drinking water exposure to a mixture of atrazine metabolites and nitrates during the second trimester of pregnancy and prevalence of small for gestational age (SGA) neonates. We conducted a historic cohort study in Deux-Sèvres, France between 2005 and 2010, using birth records, population census and regularly performed drinking water withdrawals at community water systems. Exposure to an atrazine metabolite/nitrate mixture in drinking water was divided into six classes according to the presence or absence of atrazine metabolites and to the terciles of nitrate concentrations in each trimester of pregnancy. We used a logistic regression to model the association between SGA and mixture exposure at the second trimester while taking into account the area deprivation measured by the Townsend index as an effect modifier and controlling for the usual confounders. We included 10,784 woman-neonate couples. The risk of SGA when exposed to second tercile of nitrate without atrazine metabolites was significantly greater in women living in less deprived areas (OR = 2.99; 95 % CI (1.14, 7.89)), whereas it was not significant in moderately and more deprived areas. One of the arguments used to explain this result is the presence of competing risk factors in poorer districts.

Associations between life contexts and early sexual initiation among young women in France

CONTEXT

Early sexual initiation (before age 16) has been linked to an increased risk of teenage pregnancy and STDs. Most research on correlates of early sexual initiation is from the United States; no similar work has been conducted in France, where the sociocultural environment differs.

METHODS

Cross-sectional data from the 2010 Health Behaviour in School-Aged Children survey were used to examine the relationships of personal, family, peer, school and neighborhood characteristics with early sexual initiation among 1,094 French females in grades 8-10. Two-level logistic regressions were used to identify associations.

RESULTS

Twenty-five percent of respondents had had sex before age 16. Early sexual initiation was primarily -associated with individual-level characteristics. Young women had an elevated likelihood of having initiated sex early if they went out after school at least four times a week (odds ratio, 2.0), had repeated a grade (1.8), lived with a single parent or in a stepfamily (1.8 and 1.5, respectively), perceived a low level of parental monitoring (1.6) or had two or more male friends (2.8). At the environmental level, respondents who attended school in areas with a high proportion of residents who were foreigners had a reduced likelihood of having initiated sex early (0.5-0.6).

CONCLUSIONS

Although early sexual initiation in France was essentially linked to individual-level variables, further research is needed to understand its relationship with neighborhood characteristics. Such studies should include additional environmental variables, test new hypotheses and employ a longitudinal approach.

General practitioners can evaluate the material, social and health dimensions of patient social status

Objective

To identify which physician and patient characteristics are associated with physicians' estimation of their patient social status.

Design

Cross-sectional multicentric survey.

Setting

Fourty-seven primary care private offices in Western Switzerland.

Participants

Random sample of 2030 patients ≥16, who encountered a general practitioner (GP) between September 2010 and February 2011.

Main measures

Primary outcome: patient social status perceived by GPs, using the MacArthur Scale of Subjective Social Status, ranging from the bottom (0) to the top (10) of the social scale.Secondary outcome: Difference between GP's evaluation and patient's own evaluation of their social status. Potential patient correlates: material and social deprivation using the DiPCare-Q, health status using the EQ-5D, sources of income, and level of education. GP characteristics: opinion regarding patients' deprivation and its influence on health and care.

Results

To evaluate patient social status, GPs considered the material, social, and health aspects of deprivation, along with education level, and amount and type of income. GPs declaring a frequent reflexive consideration of their own prejudice towards deprived patients, gave a higher estimation of patients' social status (+1.0, p = 0.002). Choosing a less costly treatment for deprived patients was associated with a lower estimation (−0.7, p = 0.002). GP's evaluation of patient social status was 0.5 point higher than the patient's own estimate (p<0.0001).

Conclusions

GPs can perceive the various dimensions of patient social status, although heterogeneously, according partly to their own characteristics. Compared to patients' own evaluation, GPs overestimate patient social status.

Measuring social inequalities in cause-specific mortality in France: comparison between linked and unlinked approaches

BACKGROUND

Monitoring the time trends in socioeconomic inequalities in mortality by cause is a key public health issue. The aim of this study was to compare methods to measure social inequalities in cause-specific mortality in the French population aged 25-55 years. More specifically, it compares bias and precision related to the use of occupational class declared at the last census (linked data) to the one declared at the time of death on the death certificate (unlinked data).

METHODS

We used a representative sample of 1% of the French population. Causes of death were obtained by direct linkage with the French national death registry. Occupational class was classified into eight categories. Taking professionals and managers as the reference, relative risks of mortality by cause and their 95% confidence intervals were estimated using Poisson models for the 1983-1989, 1991-1997, and 2000-2006 periods. The relative risks were calculated with both linked data and exhaustive unlinked data.

RESULTS

Over the 2000-2006 period, occupational classes declared at census and on the death certificate were consistent for half of the deaths. Relative risks for manual workers were found to be similar between the two approaches over the 1983-1989 and 1991-1997 periods, and higher for the unlinked approach over the 2000-2006 period. Over the latter period, the order and magnitude of relative risks varied similarly by occupational class and cause of death for both approaches. Confidence intervals obtained from linked data were wide.

CONCLUSION

Occupational class derived from the death certificate must be used with caution as a measure for epidemiological purposes and the available linked data do not allow accurate estimates of social inequalities in cause-specific mortality. Other solutions should be considered in order to improve the follow-up of social inequalities in mortality. This would require the collection of educational level on the death certificate or the linkage of the cause of death database with other exhaustive and informative databases.

Physical activity in the prevention of childhood obesity

The current high prevalence of childhood obesity and its co-morbidities is concomitant with a low level of physical activity and an abundance of sedentary pastimes for Westernised children. To increase the participation of a majority of children in a sustained physical activity, interventions require a fair understanding and consideration of the influences of this behaviour, especially as children are overweight or obese. Basically, the physical activity behaviour of children depends on biological, sociocultural and psychosocial factors and their interplay. The recent literature lends support to the fact that some psychosocial factors such as self-efficacy and physical competence may be solid anchor points upon which to improve the participation of overweight and obese children in free-living physical activity. Thus, interventionists should first concentrate on improving these personal dimensions around which physiological and environmental factors might revolve. The development of motor skills may be a good means for enhancing the self-image of obese children.

Education as a predictor of chronic periodontitis: a systematic review with meta-analysis population-based studies

BACKGROUND

The impact of socioeconomic inequalities on health is well-documented. Despite the links of periodontal disease with cardiovascular diseases, adverse pregnancy outcomes and diabetes, no meta-analysis of socioeconomic variations in periodontal disease exists. This meta-analytic review was conducted to determine the extent to which education attainment influences risk of periodontitis in adults aged 35+ years in the general population.

METHODS

The authors searched studies published until November 2010 using EMBASE and MEDLINE databases. References listed were then scrutinised, our own files were checked, and, finally, we contacted experts in the field. The authors included only general population-based studies conducted in adults aged 35 years and more. All articles were blind reviewed by two investigators. In the case of disagreement, a third investigator arbitrated. Using PRISMA statement, two reviewers independently extracted papers of interest.

RESULTS

Relative to the higher education group, people with low education attainment experience a greater risk of periodontitis (OR: 1.86 [1.66-2.10]; p<0.00001). The association was partially attenuated after adjustment for covariates (OR: 1.55 [1.30-1.86]; p<0.00001). Sensitivity analyses showed that methods used to assess periodontitis, definition of cases, study country and categorization of education are largely responsible for the heterogeneity between studies. No significant bias of publication was shown using both the Egger (p = 0.16) and rank correlation tests (p = 0.35).

CONCLUSIONS

In the studies reviewed, low educational attainment was associated with an increased risk of periodontitis. Although this evidence should be cautiously interpreted due to methodological problems in selected studies, efforts to eliminate educational inequalities in periodontitis should focus on early life interventions.